Currently, placental tissue is used in various wound and skin tissue treatments to accelerate healing. The placental tissue can be prepared in various forms. One form involves creating layers or membranes of material that has been dried aseptically and packaged, the material being cut into thin squares or rectangles and sterilized for future application on wounds or skin tissue to be treated.
The placental tissue has layers or membranes of chorion and amnion. These layers can be used together or separately or even combined with other layers to construct laminated multiple tissue layers of amnion or chorion or both. The dried layered material when applied is typically rehydrated prior to being applied. The processed placental tissue material when made into a single layer of amnion or chorion is extremely thin and translucent making it difficult to discern sides. An epithelial side is on one side and a stromal side is on an opposite side, distinguishing the two sides is difficult.
U.S. Pat. No. 8,460,715 B2, assigned to Mimedx, teaches the layer or membrane can be embossed with indentations or bumps to indicate a top or bottom surface. In U.S. Pat. No. 8,597,687 B2; also assigned to Mimedx, there is a method of placing an asymmetric label on a portion of at least one side of the tissue graft in order to distinguish one side from another. In that patent, the label is also part of the membrane created by embossing or indenting.
The present invention achieves this ability to discern sides, but in a completely different approach which is unique in that it also greatly facilitates handling of the tissue during treatment so applying the layer is achieved without wrinkling, folds or other issues commonly found in practice. The single layer placental or layer membranes when rehydrated has a tendency to cling to itself like thin plastic film used in wrapping meat, this causes wrinkles and reduces surface contact on the wound to be covered. The present invention, as described herein, solves these issues in a simple and very reliable manner.